well lets think this through...premade plans are really not going to be of much use to you in your situation especially if you are trying to attach it to the existing walls (highly suggest this for stability especially in the size it will end up being). Stud placement in the walls (or are those walls concrete cant tell with pic?), doors, what exactly you want out of the wall (angle, etc) all make the idea of premade plans kind of pointless.

Where do you live? I have built 4 walls previously, two small bouldering caves, one off vertical ARC wall, and a giant multi-wall bouldering cave for a school. If you are serious about hiring somebody, then I would take the contract if you are ready now and somewhat close to where I live (southeast US).

Thanks again for the reply. I live in Dubai, which I am guessing is not too close to you. Just out of interest, what sort of cost would you estimate to finish a wall with two sides and a roof. The walls are concrete by the way.

yeah thats a no-go unless of course you want to fly me out to Dubai I've been wanting to visit and jump at the Dubai skydiving dropzone for a long while now

Cost for the wall would be approximately 600 USD for lumber/concrete bolts/screws/plywood/t-nuts. Then about 400 USD for holds to start. That would be a very complete wall. You could do it for less initial start with room to expand over time especially if you were OK with dropping the density of holds down initially.

Funnily enough, I drive past the drop zone quite regularly. It's surrounded by sand, so if you get blown off course, you still have a soft landing. I'd be more than happy with those prices. Unfortunately, my budget would not extend to your flight. Thanks a lot for the advice though.